I wrote MadMACs awhile back, as a
simple script to randomize my MAC address (and host name) in Windows on every
boot. I had not updated it in a long time so it stopped working well in newer
versions of Windows (Windows 7, Windows Vista and Windows 8). When someone
would try to get MadMACs to work on a newer version of the OS, Windows would not
always respect the registry setting for what MAC address they were suppose to
use. Seems that if it is a wireless interface, the 2nd nibble has to be a 2, 6,
A or an E on Windows Vista and newer. I included functionality in the new
version of MadMACs to make sure this nibble is correct if you tell it the NIC
you are trying to change/randomize the MAC address on is a WiFi card. I've also
added a GUI for configuring your MAC addresses on your network cards (the old
version used prompts), made the config file more INI like, and made it so that
MadMACs itself can reset your adapter and start using the new MAC address
immediately (name changes will take a reboot).

Source code is included. Here are the simple directions:

1. Place the EXE where you intend it to be ran from.
2. Choose the interface to configure.
3. Set a prefix (or the whole MAC address if you don't want to randomize) you
want to use.
4. Set the "Change Default MAC address on this interface" check box.
5. Set "Check if this is a WiFi NIC (or some problematic wired ones) under
Vista/7/8 (2nd nibble randomly set to 2, 6, A or E)" however you want.
6. Click "Save/Apply" to save and apply you MAC address settings.
7. Toggle "Run On Startup" as you see fit. Turn it on if you want to randomize
the MAC address on every boot.
8. If you want to rename the computer on each boot (useful for some DHCP related
logging issues), rename "Sample dic.txt" to "dic.txt" or provide your own
computer name list text file in the same directory.

Enjoy, and I take no responsibility if it screws anything up. It's been
working fine in my Windows 7 64bit test environments so far.

Notes from older, pre-2.0 versions

Description:

I hope you enjoy this little MAC
address and host name changer. When Glj12 told me about his host name
randomizer, I told him about my desire to make a MAC address randomizer. We
decided it would be cool to rap them both together, so I ported parts of his
VBScript to Autoit3.

MadMACs was designed with the
privacy paranoid in mind. The two main things a DHCP server records when you get
an IP from it is your host name and the MAC address of the network card you are
connecting from. This is identifying information that not all users want to
leave behind. MadMACs allows you to randomize this information after it runs and
reboots.

The first thing you should do is copy
MadMACs.exe to what ever directory you plan to have it run from. If
mac-config.txt does not exist in the same directory as the binary a wizard will
come up and guide you through configuring which adapters get their MAC addresses
randomized. The Wizard will ask you what prefix to use on the MAC address, keep
the default 00 unless you want to use a specific vendor's MAC address range. For
a list of vendor specific prefixes see:

This wizard also lets you set a
registry entry to automatically run the randomizer on start up. There are two
possible command line parameters:

config
Brings up the setup wizardremove
Removes all of the registry entries.

If you run MadMAX without
parameters you are asked "Do you wish to remove MadMACs from startup and clear
the registry? Click No to configure MadMACs instead or Cancel to forget the
whole matter." Make the logical choice to get the desired outcome.

If you want MadMACs to randomly set
your host name make a text file called dic.txt in the same directory as the
binary. This text file's format is one word after another separated by line
feeds. If you are feeling lazy just rename the file "sample dic.txt" that comes
with MadMACs to "dic.txt". MadMACs will randomly select a word from dic.txt and
make that your host name. You may not want to use the host name randomizing
functionality if you need to reach the host with the same name every time.

Most of the setting don't take effect
until the computer reboots (sort of :) there are exceptions, like if you disable
and enable the adapter). Basically, the current session randomizes the next
session. If you have questions about the code, ask on the Binrev forums so I
don't have to answer the same questions over and over again in email.

I take no liability for the misuse of
this code. If you mess up your system or network with a bad MAC address or host
name it's your fault. Use at your own risk. I've only tested it in Windows XP,
and Vista so far. Consider this code GPLed.

Side Notes:

A patron of my website
pointed out that MadMACs, and other similar tools, seem to have a problem
randomizing the MAC address under Windows Vista if you are using the Intel
Wireless WiFi Link 4965AGN chipset. It will work with the 4965AGN if you
randomize only the last two digits, and start it with the prefix 1234567890. It
will also let you set the whole MAC address to DEADBEEFCAFE, or even let you
randomize all 12 hex digits. However, if you take the default prefix of 00,
MadMACs will make a random address up and put it in the NetworkAddress registry
value, but the 4965AGN chipset drivers will not honor it. If anyone knows why,
please contact me.

Ver. 2.0: 12/26/2012 GoHP from:
http://gohpdee.com/ told me awhile back a few tips of how things have
changed in versions of Windows post XP (Vista, 7 and 8) when it comes to setting
a MAC address. Seems that if it is a wireless interface, the 2nd nibble has to
be a 2, 6, A or an E. I included functionality in the new version of MadMACs to
make sure this nibble is correct if you tell it the NIC you are trying to
change/randomize the MAC address on is a WiFi card. I've also added a GUI for
configuring your MAC addresses on your network cards (the old version used
prompts), made the config file more INI like, and made it so that MadMACs itself
can reset your adapter and start using the new MAC address immediately.

Ver. 1.2: Qwasty
let me know that if host name randomization is used with MacMACs, and the host
name is over 15 characters (or has certain bad illegal characters) it can cause
all sorts of lsass.exe errors on boot up. To fix this, I've updated the code to
do some sanity checks on the possible hostnames given to it in dic.txt.
Hopefully this fixes the problem. I also compiled it with the newer Autoit3 v3.2.12.1.

Ver. 1.1: Added better Vista support. It's compiled with Autoit3 v3.2.1.14 (beta),
so older versions may not compile the script right. When you login to Vista you
will still have to either tell it to run via the error message you see in the
system tray about start up apps, or just turn off User Account Control (UAC).